title: The effects of ampicillin on oral contraceptive steroids in women.
abstract: 1 Thirteen women taking long term oral contraceptive steroids were studied while taking ampicillin (500 mg three times daily) and compared to a control cycle while not taking ampicillin. 2 There were no significant changes in the plasma concentrations of ethinyloestradiol, levonorgestrel, follicle stimulating hormone or progesterone, although lower concentrations of ethinyloestradiol were noted in two women. 3 We conclude that most patients taking oral contraceptive steroids do not need to take alternative contraceptive precautions while taking ampicillin.
mesh_terms: D000328:Adult; D000667:Ampicillin / Q000097:blood / Q000494:pharmacology*; D003276:Contraceptives, Oral / Q000097:blood*; D003278:Contraceptives, Oral, Hormonal / Q000097:blood*; D004347:Drug Interactions; D004997:Ethinyl Estradiol / Q000097:blood; D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D016912:Levonorgestrel; D009640:Norethindrone / Q000097:blood; D009644:Norgestrel / Q000097:blood; D011374:Progesterone / Q000097:blood; D013997:Time Factors
chemical_list: D003276:Contraceptives, Oral; D003278:Contraceptives, Oral, Hormonal; D009644:Norgestrel; D004997:Ethinyl Estradiol; D011374:Progesterone; D016912:Levonorgestrel; D000667:Ampicillin; D005640:Follicle Stimulating Hormone; D009640:Norethindrone